The Research Of The Sustainability In Basin Scale Based On The Integrated Water Ecological Carrying Capacity Method

Water resource, water environment, and aquatic system have faced degeneration and even breakdown because of rapid exploitation and extreme urbanization. Based on the review of the concept and the method of the ecological carrying capacity, the SNI integrated ecological carrying capacity model was built according to the theories like the sustainable development, the integrated ecosystem, and the dualistic water cycle and the methods like the system dynamics. The SNI model was used to assess the status of water ecological system and predict the change of carrying capacity by adopting the multi-scale water ecological footprint. The sustainable case on water ecological system in the Liaohe basin was presented according to the simulation result of the SNI model.The results of our research were list as follow.1. In city scale, the status of the water ecological carrying capacity is decreasing from the upstream to the downstream. The ecologcial press index (EPI) of Benxi in upstream is0.5which is the least, the same value of Shenyang in middle stream is2.4. The EPI of Panjin in downstream showed that the pressure reaches14times of the carrying capacity. In time series research, the ecological pressure is increasing and the EPI value in2030reaches1.43which is1.15times more than the same value in2006. In the structure of the water ecological footprint, the water ecological carrying capacity is mainly consumed by the agriculture.2. According to the current pattern of development, the simulation showed that the water ecological carrying capacity cannot afford the sustainable development. The scale of population is shruken from12.32million to11.64million. The growth of economy is deceleration (GDP is2500billion CNY.). The imbalance between the supply and the consumption of water resource is more obvious (The gap between the supply and consumption is10billion m3). The gap between the NH4N emission and environmental capacity reaches to15000t in2030. The result shows that the carrying capacity under the environmental tax is more reasonable and more sustainable than that under the pollution fee policy.3. The result showed that the optimal coefficients indicated that the growth rate of population and GDP are1%and7.1%. The rate of agricultural investment is0.105and the rate of agricultural benefit is0.25. The rate of return on investment is0.742.The research above all indicated that the multi-scale water ecological footprint is more reasonable and dynamic than tradional methods, meanwhile, that the pollution was considered into the water ecological footprint. It makes the method more universal and more practicable. The SNI integrated ecological carrying capacity is a more reasonable method based on the multi-spatial-scale integrated ecological system in the basin scale. By comparing the cases and simulation, the more sustainable develop case was presented in our research.